At STP, what is the volume of HBr that will result from the reaction of 10 liters of H2 and 10 liters of Br2?

Question

Work would be nice :]

Answer 1

H2 + Br2 ==> 2HBr.

When all are gases, one can use volume directly and not go through converting to moles.
10 L H2 x (2 moles HBr/1 mole H2) = 20 L HBr.
10 L Br2 x (2 moles HBr/1 mole Br2) = 20 L HBr.
So 20 L HBr is the product.